SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b968ec2cb14165426223b2c431b2161861ae04b9fb537086d367b4e6b478f91' 
  AND token = 'JelPlRN3RGbbdqKo0gyB+TEHT+jdYkmWQ1oJgAg+Vn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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