SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ead7588fc3ddaf3b5ac141a5b3350201c1fc937ea2a931496f6887ef7dc755cd' 
  AND token = 'HVvbyEfrDOaisVDRmoSH0uD7wCLDgdJtCGtVdpdbJk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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