SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11387c8f9126836701cc980152937daa04059eb46a5d4944bfb3b0b68aa0e25' 
  AND token = 'jNZusF1gxFpqdXnVbIIn+Z7yy6ukaPwP0qby08OpZFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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