SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad951dc92caf8c052d3ed72bb465b745710f53e609ad8c1bca1af8eb69b422f5' 
  AND token = 'QqRYqvwzXMz8LsGKjRL4YwrEh/vP6uhQ1ASPepF9aV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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