SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '246838ec859ff49469a3a7d24d182a4867a0768b414cefe7c2d3b14d5e7cd5e6' 
  AND token = 'SDS4HwtYeKVgAoZAFJIlATgLfamNOFgNAfL22LtUfEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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