SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92a0958bf0dd76d0a5886cafc8e518f41338a1475238e16d51c2973d9fe2a48' 
  AND token = '2kAzDEocfXgbsHBJZGw3c+mFlhk0xrKHSkl9hLpjBco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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