SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27041857228038afc7f2b37887c883b2c6b906912f2a48ed7f4c1a231e51a465' 
  AND token = 'VXKF/mS2EubkCT2hTtxnP06czMYjlqUTKfmQZmfbcZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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