SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f81aa0b53e4b70f8ff80365915b99805f272acd172b8ae6cd9780187cec98ae' 
  AND token = 'VOMLYXgagE/4RRtMhD5hngi9rUX/zM8PKZ+QNw83qbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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