SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5290e5eb960b0cb5865ecc7374d421975a0e7abebb2e7e06f5b1f7d7dcbee222' 
  AND token = 'GPQYquSRrAUDPaGc1noU1Xi5C3pupVBXeIZRS1g2MeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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