SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c956e7fcebd9b1f947947af141f6b7b93570c1f565b7fe9923f8135cff51ae52' 
  AND token = 'LVH8VPNsxjqalyogszPFdMHKiovIk88vx6Q0G/Kko0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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