SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe6372de22fed8b193ba213df5d891790995e0ab128a471f3e7e749bc0faa5ce' 
  AND token = 'SVcEMxJzlKYNVCgU8YRZGUXgP4x8+jd9nr0N7gQAic8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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