SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1e4930e4977eac769533faefc5ebce448a5f1fbeef1990f3361255c42d34a01' 
  AND token = '9qtpXym5n6y1GRzyKSxTouyz+Ir5kAquG92tnct338Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}