SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67803cc5c259dd0fb206566a0a5bbedeec9915f97b0c199654d3e5b268e186a5' 
  AND token = 'x3CAPQCK6IMoKXIncttCSHXQ/4IHX2rdAqyp57ZAkvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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