SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a3937a00a0989ff7a14099446d85659c4d535cfe0dd509fe4c5e7c476c70ff' 
  AND token = 'zD6lfdc0pLAdLp/i3m7++OXk61QHB4ci4CIfsI0sOV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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