SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54278caa205da13c8fa4ba374b7a1bc0e8ff556808db292bc3eedf8ec3e3957b' 
  AND token = 'AzGmN6FKiv9q8gNtyA7CegsR79TqrK8Ba3bRqdl//a8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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