SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5004834d7a8b4130bc5036f638ed78e91365b59059570970b30730b7bfa09b1b' 
  AND token = 'fePV/sT/buUEcRbgWTOPsFi3JfJ+iOiT57e+lmxRZnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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