SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53e3da01938f25e13b2509b9325f87bf8a82df850de3f909c44265696fe199ea' 
  AND token = 'jvg+lhM4CGMXo9TXa92K5E45yf9Am7JSL8M8pEkBYPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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