SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a65816edabef9a752a7d309bbe37ec3a7c429d00b735cc784a23740e101af1d7' 
  AND token = 'LcUiLOnK039/VOXYFNYrZ2RtQ1uCorF4VRA3NHLH+Qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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