SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eb179a9e3be65093b4891281ee79d82f1dee2a7fda6b93b1cbb5fd8ff7f4722' 
  AND token = '3FcJEvhQnB1fxpPdQjxc1UXGsKHugSxh+4bnQkhYqU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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