SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aff18b6aecc55c345d99fc3c96d99f3d5bdb64c2b75fac52ddd10935c36f02d4' 
  AND token = 'dsMOuN3Gq+rHruzTZJTU19PoF32swmG4jBgtsow70Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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