SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cebab5521de529993ea23a9f4994a9be73fa2ca15f559776cf131043d443d855' 
  AND token = 'VHX/+dAy4EuxfFZFXHvrIOl1/k+gKbKk46+Un20U48s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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