SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48dcaea2dc6a6af398248bdd921ad4c9fa41aaf8526098b12781db7297e2b5ed' 
  AND token = 'LIl3cDMJWFwTswUg9FThSnfEv3mw2SHpCERqtGhF1AM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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