SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe059448941b30259bc099f7d783f7f3aa6c215647b457fd420b39a2fc365682' 
  AND token = 'zCu4MwkBbfFKNsEzd13VFoNzI4Og8tcbwJSNP4Iynno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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