SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9adebdcc97bf5107518f01097c435f159803a72f3f7849254de3de3d106cc74' 
  AND token = 'RXwm+FI2cT5mOLO7ZMuIIg1uOmVC8XaLDJvCNQvQBU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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