SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6f3bcfda24f00a5db3a9afdf169c6320b0220c597e83dfaa33d3a4458cf160' 
  AND token = 'VeYZHXPecxQC1B3g+OiByR3ECWz2XCbAbdMAhJRJKaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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