SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e637f9bc5944b29e8ce14defd1f6cd6afe2acb2cd957f962abc9129f2843d5e5' 
  AND token = 'ppDuxIokW+wldGBJq9E7Jzuw+cJSee5imsBgFasEX3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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