SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f5dd9a7451ce1171006c238723bce103f61fcbeec729e00ac8238711b38b98e' 
  AND token = 'A2ctgQCD4auq68G2tsoLSqY67LmmOy9wBvpUnTXASUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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