SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e96e41ba053c960676680a2aa459916bef2bd7616cd304276a281cdb7e80686e' 
  AND token = 'h0H36xCx/NsT2YTkgcIFFyA+tosVpd1HKgKQhSv+vS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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