SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30115173583c91042e0178e50c1025f9585fab5dcdc36f7f5794b5abc96d021a' 
  AND token = 'PNUiVWFBjV3nZX9deav5wWJHksRZN4PJjwaMajrFdBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}