SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12a527b2a97a031abec0b840d8ef061cb08fc3224c8ca4d8fafaf561605fb3c8' 
  AND token = 'yXu0UnCqL5Wzc3W07VJfXUNpwSmQicQ93CNj+8fztPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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