SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afe19efff98bce8fb2a05723e81ca12abf7b437477813e3316e52d85df078926' 
  AND token = 'HbOUjgaWz0bWa4U3rG7rXAKaSQoNPixOoQ8dyYnGGqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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