SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2f0c793dfacbcc1c51b8304aa1718d042e86fee8dee59717583e51db1714fd6' 
  AND token = 'CIMUCG4AJI64pRT0QJst4dVGxqgAswGVBOwFHtjshHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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