SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '58a87a5e6301be45f783bbfc8a48146cde72969e8f0b5cf17925737e771656c2' 
  AND token = '6KISGBjdPiE5MZp0kAFgdmVQ+ii2H6irLQOq+FNFY8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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