SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eefbb40e9622409a9d417634ed670a2fd56a70afa81f9cb91633fc0cee3a204e' 
  AND token = 'BmsHQDYHEbbYUmcvZyIybevkZ3Zp2rIriCTzbFH5y2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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