SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19c34ee55b0979106056a543324948a663457ccec96c59bc8f67f008f84bfabf' 
  AND token = 'zEAF+2MacEb3w7kgELT8HJyhfeJpFuHR1GaClG6LgSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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