SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abc6ffc20111f479d035e6e1a2a1ea88bc370bc7dbacc897b62ffe01119f1070' 
  AND token = 'GKDg0muspeaQpKIiPaeFiwY8bNnaBU4+auO+3c7QuJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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