SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6205cf101177dee6189693997ed42fe59dd65622a762f47897f6c3817643db91' 
  AND token = 'WWfcYEMjsb3+I6tTpXBKee6ibGd221YoNuhEG77IAh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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