SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd3134791739f48dee4ff08561deede1c2c96fd67f5094f718baf5153e1fe32' 
  AND token = 'JKTtCcdYAlsr33GduFXk8aImrmIzvIxd0qye0c2EaNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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