SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d88e436fd9148e35dd15cbbdd346cbbca0bbdc09cb8f2494d7c11605f308500' 
  AND token = 'h2jPMCEdexTP5QtRn4n0AwcZAN0cFtNISBtyCoZR6h0=' 
  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"
    }
  }
}