SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '437ca50952921f27e314aaf4835614cf2cbbc769602cc2f27d778b3539dcd1b4' 
  AND token = 'B41fG+jzHespegZPU79k8vEQbWH2Ejrz+E+Fl/VCq+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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