SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3e9c983857c1051bb329263c7bdcb6d3de819074d3734bfbecd6753daac5ed5' 
  AND token = 'WWMRcNE2+Zr4C6ZY4+MEXiF77BjmMraZc4aKHaD57IU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}