SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f75db3bfdb8fafab3344aab44edb66945a071a66afcda764c2edb4e273988886' 
  AND token = 'ILFDVbognWnQZqOWbUXgF3ykUwUSGxM1/jKwUKn1EAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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