SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d740ea50f22b30187a0ae67689f259f7a3ab53c82b53d2788b9b22935c46507' 
  AND token = 'grFhSmdV0uLAo26aYN4voz/KiR/hJA+1LB2GAOpKQRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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