SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '550a5734e67084293bdf6f2cf5df43f73f49328b2ea71c3923c26033b15d627b' 
  AND token = '+PyLIot0+dEqRLfAomlKOGVS1hLkZPbyKNOLHgXwHkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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