SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a66d0feaf57a880d636652e635e504b46b170550f4613bf2167435f79bc89f8a' 
  AND token = 'WP9YfgPSwrzjIydQuFVk4EeS6T+GNK9nxTLHMZ/tsdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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