SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '145978ca0e3b0c8c377ced947c81a392bee07a6967e633f75ec97d794062ad27' 
  AND token = 'uEMr3zN0asuwhbxjb2wVhlWzf5vTq6kGxgCvHhjgUUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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