SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5655e9940f9e6513afc38154ce6927fbee99504aeea9ac1c01619fb20420f48' 
  AND token = 'rpCQ3RufaIoyrR5LHILY9zFg4WiEtM2kZdiWVtRivjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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