SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baa46cc529f06eeb9ea9dce37cff4c732cfadc327e6a71b68b3efe8461b068b2' 
  AND token = 'r2APGY3pfzzNM6cernYiuOBnjOC76y0OkpElk8ix5Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}