SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94ac0c50371ac19b32f772264573b22a5e69bfd38a293a98989473096c0d850b' 
  AND token = 'eek1YDwDITWZMjbddaGciAMggOro/LDUhHp0mRYVapA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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