SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45bf54a6faf5b597c394feeb14e248169ae1e8cd37814d9e114169cc78209431' 
  AND token = 'CgJkFMGekifGI4sUZXS7t3+ShH2PArsrYz0VYjM7Fks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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