SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b4e8a203f0f7f5a129d608dd0755105e93903717fd26c23a407492be9d18547' 
  AND token = 'eOHX/cfHIjh6DurPm+6pzYP/GZo8RvgsAMtdDedAFqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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