SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8f3a49bf724e9045d309c3c22fd3dd86500bad8564d15735553100ba66a746' 
  AND token = 'xPwUtQi4tLJ8gTnWUbOts4vtFRrNxybpIZl03KdC2TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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