SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b90c704f2f336fcda62093584ae7153d3f42a2351d6f330b7ef8af11ddf04a1' 
  AND token = 'ipj33OCtYK3quCrt4vncNbehTceGELDkEmRBj3rlkiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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