SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bcf1d22df49b88615ae9202f632d6b037d50007562dc0eadb6059ee94f56866' 
  AND token = 'hculmJGfvT53qLIPpbWRrNKZhv0fYCpH4w7hYr+UFko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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