SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c61107755dc964b2de5db65daddf6befab10f6edd75356d47d4e0ed3161b14e' 
  AND token = '3jXPEKDi5IBYa+VtdUIPyhbLugl6Xw0EnQgHeUN3uxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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