SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7fe16f6b22022eb4821aac96853a258966ea7b0639dbad6069f82721361d096' 
  AND token = '70lWLMu4T1fMaNF3QJUxw2YAPfuvXr6MtPzNkMtgbsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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