SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '853cdafcaee9ac0632531310486ab51ed2056de5570dd42e21ea240b8f95b554' 
  AND token = 'eFY7gC/gmLePotolss2Om29cduf/S8ZiIpHukI4MiMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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