SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a30838ab7479c60f4ef1a2c437cda61a649440cc99005eaad5d9b2e074fce9' 
  AND token = 'AcOmxDVhHIzXrO9eIfFGevJImIB2r55MmdVkd6tIYww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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