SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b99aec4cdddc8d1735ed09d15cda5632c3221fd550b23d41a9a0f53aa08f6b5' 
  AND token = 'f+uh3dL5Vd71DL+NjkPAJHovQkTo1ngDjkScKvDhI+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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