SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4243f1241fa67cccbb48f56dd9da3f090a0ec7310811b47d0e0c4a3b05786e8' 
  AND token = 'JIXnRhUrhK3Lhoyp+eQBigjPbfZzFrPCvam06inCWCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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