SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82dc2cd45911c62da573593e12ec02264c40db5b6b52677bdd452f5ef40ef731' 
  AND token = 'EHrZ3IZuHCMDXCr5YSV5PWVSGZPw3z1zrlQyhsLhqvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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