SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff1928043131f6985cbe8099848c086b1b173ca6a342201daf9719b46ccf6eb9' 
  AND token = 'njasjJh7GEF/20HmLtWMVCgc3wsLZJU8XUbkhmuEg7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}