SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3207e3f5f898a6b12e4531415fca4e72573aef8ccfcc17cf06d64421777ed6fe' 
  AND token = 'Qg6ndKLqdrSHy12lkVeDXUx0TToTLJLQY9SQmjTnzNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00084

JSON explain

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