SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a58bba91f58929e007ba5d9958f4e7a434b9a87810ae68510c8c1412da367ad' 
  AND token = 's2M8KcgG1bBDZPkWkTJZrBav/SOyB/ILWk3WYQyh5kE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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