SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7edc4b0365f8ca3b9f9a4484a5c0384c2c6ce989e791f0c0b08841bc8edc38e8' 
  AND token = 'lLih2/kCLHhKnlo/pXVtV2++qFSdPjJK8Dt24lE5o44=' 
  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"
    }
  }
}