SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7825f9d62e434beeff903cc687e7f91fdf79da544a62adc09da5193364973390' 
  AND token = 'piDeA7loV29wym+hJKFOZkP73nzJhybKZt/D3Fsv1PY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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